In the past, interfolding machinery has required the use of relatively complicated interfolding rolls to accomplish the interfolding of cut sheets from one or more webs of material to obtain a stack of interfolded products such as paper towels or facial tissues. Such prior art folding rolls required articulated mechanical grippers having a number of moving parts and requiring relatively complicated drive mechanisms to move such articulated parts at the proper times and to the proper positions to accomplish the interfolding. An example of such prior art mechanisms is shown in U.S. Pat. No. 4,270,744, entitled Tuckers on Mechanical Folding Rolls, the disclosure of which is incorporated by reference.
The present invention overcomes the relative complexity and associated cost and reliability problems of such prior art systems by providing interfolding rolls having vacuum tuckers and grippers which operate without moving parts to accomplish the interfolding of cut sheets of porous material, eliminating the need for complicated and sensitive drive mechanisms which were required to be coupled through the folding roll to actuate the mechanical grippers.